大鼠弥漫性脑损伤后早期病理学及烯醇化酶表达

目的观察烯醇化酶(NSE)在弥漫性脑损伤(DB I)动物模型中的变化。方法采用M arm arou的弥漫性脑损伤模型,于伤后15m in,30m in,1h,3h,6h,12h,24h取脑组织,运用免疫组化SABC法染色结合北航MAIS图像分析系统进行图像分析。结果打击后15m in,阳性细胞灰度值较正常对照组减弱,随伤后时间的延长,灰度值持续下降,伤后6h为最低(P<0.01),伤后24h仍显著低于正常对照组。伤后12h阳性细胞数明显减少(P<0.01),并持续到伤后24h。特殊染色观察到轴突断端球形改变及神经纤维脱髓鞘改变。结论DB I具有复杂的病理学改变,烯醇化酶(NSE)可用于早期鉴定及损伤经过时间的推断。     

等位基因分型标准物的法医应用及制备研究

短串联重复序列(shorttandemrepeats,简称STR)由于其本身的优点和检测技术的不断完善,在今后相当长的时间内仍将是法医应用的重要遗传标记。等位基因分型标准物是STR检测试剂盒的组成部分,能够保证各等位基因分型的准确性。本文对等位基因分型标准物的出现、在法庭科学上的应用以及目前制备方法进行了综述,并对各种制备方法进行比较,以期对各实验室按照实际需要自行制备相关STR的等位基因分型标准物在方法选择上有所帮助,从而更好地进行法医物证鉴定。     

利多卡因硬膜外麻醉和静脉注射致死的动物模型

目的建立利多卡因硬膜外麻醉和静脉注射致死的动物模型。方法本地杂种犬18只其中6只经硬膜外腔、6只经股静脉注射利多卡因(63.35mg/kg体重),对照组3只经硬膜外腔、3只经股静脉按注射生理盐水(3.2ml/kg体重)。观察动物致死过程的生命体征变化及死后各组织器官的病理改变特点。结果硬膜外麻醉致死犬心电、血压和呼吸消失的平均时间分别为28 min(22~45 min)、23.6 min(20~42 min)、22 min(18~35 min);静脉注射致死犬血压、心电和呼吸消失的平均时间分别为6.5 min(5~8min)、8 min(6~10min)、7.2 min(4~9min);各器官病理改变均呈淤血、水肿等征象。结论该模型实验动物的表现和生命特征变化符合椎管内麻醉中毒、致死的表现,可用于利多卡因麻醉意外致死案件的法医学鉴定研究。     

中国司法鉴定的古代史

公元前7世纪至公元前5世纪,是我国司法物证出现的萌芽时期,我国司法鉴定活动中以法医学为代表的最早时期也是出现在周朝。秦代在审理案件时,已相当重视和广泛使用各种司法物证,指纹的运用就出现在该时代。东汉时已形成简单的法医检验初步方法。三国时期司法物证检验的范围较前代有所发展扩大,从死因检验、伤痕鉴定,到笔迹检验、弹丸鉴定均有出现。以后各代出现了大量法医学著作。     

An evaluation platform for forensic memory acquisition software

Memory forensics has gradually moved into the focus of researchers and practitioners alike in recent years. With an increasing effort to extract valuable information from a snapshot of a computer's RAM, the necessity to properly assess the respective solutions rises as well. In this paper, we present an evaluation platform for forensic memory acquisition software. The platform is capable of measuring distinct factors that determine the quality of a generated memory image, specifically its correctness, atomicity, and integrity. Tests are performed for three popular open source applications, win32dd, WinPMEM, and mdd, as well as for different memory sizes.     

Y-STR analysis on DNA mixture samples—Results of a collaborative project of the ENFSI DNA Working Group

The ENFSI (European Network of Forensic Science Institutes) DNA Working Group undertook a collaborative project on Y-STR typing of DNA mixture samples that were centrally prepared and thoroughly tested prior to the shipment. Four commercial Y-STR typing kits (Y-Filer, Applied Biosystems, Foster City, CA, USA; Argus Y Nonaplex, Biotype, Dresden, Germany; Powerplex Y, Promega, Madison, WI, USA; and DYSplex-3, SERAC, Bad Homburg, Germany) were used for the amplification of the mixture samples. The results of the study showed a striking inter-laboratory difference of kit performance as determined from the peak heights of the obtained Y-STR genotypes. Variation in quantity and quality of the shipped DNA can be excluded as reason for the observed differences because both samples and shipping conditions were found to be reproducible in an earlier study. The results suggest that in some cases a laboratory-specific optimization process is indicated to reach a comparable sensitivity for the analysis of minute amounts of DNA.     

PCR-DGGE法检测浮游生物16S rDNA在溺死鉴定中的应用

目的建立并评估PCR-DGGE法检测浮游生物对溺死鉴定的应用价值。方法大白兔30只随机分为3组:溺死组(n=12),死后抛尸组(n=12)和对照组(n=6);溺死组和死后抛尸组又分为2个亚组:东湖水域组(n=6)和墨水湖水域组(n=6)。死后提取心血和肺、肝、肾、脑等组织,匀浆后,采用Percoll密度梯度离心法分离浮游生物并提取其DNA,PCR扩增浮游生物特异的16S rDNA片段后分别用琼脂糖凝胶电泳及DGGE检测分析。2个溺死案例检材同法检验。结果溺死组各组织器官中浮游生物检测多呈阳性:肺(100%)、肝(83%)、肾(75%)、心血(83%)、脑(42%);死后抛尸组仅2例肺组织(16.7%)检出阳性;对照组全部阴性。溺尸肺组织DGGE分型图谱与相应溺死点水样分型图谱相似,而与非溺死点水样分型结果差异显著。2实际案例均呈阳性。结论本方法不仅有助于定性诊断溺死,而且通过比较产物的多样性可以推断溺死地点,在法医学溺死鉴定中具有较大实用价值。     

Blind validation of postmortem interval estimates using developmental rates of blow flies

This study evaluated the use of different degree day (DD) models, developmental thresholds and developmental data sources for estimating postmortem interval (PMI) based on developmental rates of blow flies (Diptera: Calliphoridae). Blow fly evidence was collected from three mock crime scenes and sent for blind analysis of PMI. PMI estimates were calculated using averaging, single sine, double sine, single triangle, and double triangle models of DD calculation with minimum developmental thresholds of 0, 6 and 10 °C and Anderson's, Byrd and Allen's, Greenberg's, Nishida's and Kamal's developmental data sets. These estimates were compared with the actual PMI to determine which combination of DD model, developmental threshold and developmental data provided the most accurate estimate. For all three cases, at least one method gave a PMI estimation that was within 1 day of the actual date of death. There was no variability between PMI estimated using the five models of DD calculation. Overall, as lower developmental threshold increased, the PMI interval estimates increased. Depending on the developmental data set used, increasing the lower developmental threshold caused some overestimations of the date of oviposition, with estimates given that were prior to the actual death. Future PMI estimates should include error ranges, so that overestimation of PMI is avoided.     

Y- STRs and forensic parameters in African populations

Short Tandem Repeat polymorphisms have been widely studied in the world, since specific databases are required to produce correct estimates of forensic statistical parameters. In this regard, Y-chromosome STRs have been studied mainly in Europe but are relatively scarce for sub-Saharan populations, despite these populations are represented in most of the Western countries. The aim of this work is to detect groups of populations with the lowest genetic variability within the African context. This allows to establish the relative homogeneity of Y-STRs databases for forensic casework and eventually to provide a wider insight into the African genetic history.     

Genetic analysis of fingerprints—Could WGA or nested-PCR be alternatives to the increase of PCR cycles number?

In this work we aimed to compare the application of increasing PCR cycle number, whole genome amplification and nested-PCR on fingerprints genetic analysis. Results were compared for correct alleles, allele dropin and allelic dropout. We concluded that increasing the number of PCR cycles is yet the best way to attain the required sensitivity.